Painkillers are one of the most consumed medicines around the world, but they have a damaging effect on healthy tissues as well thereby making them rather risky for prolonged consumption. However, that could change soon as scientists have developed a prototype painkiller that functions like the painkillers we consume today, but without the side effects.

A team of scientists at Charite – Universitatsmedizin Berlin analyzed morphine-like molecules and their interactions with opioid receptors. They were able to successfully identify a new mechanism of action, which is capable of producing pain relief only in the desired target tissues – those affected by inflammation. They analysed the drug-opioid receptor interactions in damaged tissues as opposed to healthy tissues to provide useful information for the design of new painkillers without harmful side effects.

Based on their findings scientists developed a prototype morphine-like molecule and when tested in animal model, this molecule was able to produce substantial pain relief in inflamed tissues. However, healthy tissues remained unaffected, suggesting that the severe side effects currently associated with these types of painkillers might be avoided. Researchers were able to produce pain relief only in the desired target tissues – those affected by inflammation.

Opioids are a class of strong pain killers. They are mainly used to treat pain associated with tissue damage and inflammation, such as that caused by surgery, nerve damage, arthritis or cancer. Common side effects associated with their use include drowsiness, nausea, constipation and dependency and, in some cases, respiratory arrest.

Researchers say that in stark contrast to conventional opioids, the new NFEPP-prototype appears to only bind to, and activate, opioid receptors in an acidic environment. This means it produces pain relief only in injured tissues, and without causing respiratory depression, drowsiness, the risk of dependency, or constipation.

The findings of the study published in the journal Science could also apply to other types of pain and may even find application in other areas of receptor research thereby, the benefits of improved drug efficacy and tolerability are not limited to painkillers, but may include other drugs as well.